Building board



FIG. 1 is an enlarged fragmented perspective view of a building board of my new design, showing a longitudinal cross section taken along line 1—1 of FIG. 3, the building board being broken in the center and the end for ease of illustration;

FIG. 2 is an enlarged fragmented perspective view of a building board of my new design, showing a transverse cross section taken along line 2—2 of FIG. 3, the building board being broken in the center and the end for ease of illustration; and,

FIG. 3 is a top plan view of the building board showing my new design.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

I claim the ornamental design for a building board, as shown and described. 